This looks like a perfect fit for my use case, just downloaded it! I'm using Foam instead of Obsidian but it looks like the GitJournal author is also targeting Foam support.
You'll want to look into gitjournal. It won't work well large vaults (no wikilinks)... but it works for a separate vault with the files I want on the go. That would be shopping lists and the ol' do-queue. Dendron, a vscode extension is also a great alternate/partner to Obsidian. They both have they're strengths and they play well together as they have converged on a future-proof spec of Markdown+wikilinks+LateX. Plus you can already Publish with it using 11ty! e.g: https://texdeck.com
On the roadmap there are plans to introduce a lightweight mobile app in the near future. Here's hoping this will come soon but the Devs are doing a cracking job
Obsidian kind of gets a pass since you can sync a directory of markdown files to anything and editors are available for iOS/android. Not idea, but not going to stop you from getting ideas down into text.
Not exactly Obsidian Mobile, but should be close enough. The dev is tracking Obsidian compat issues: https://github.com/GitJournal/GitJournal/issues?q=is%3Aissue...